In an image processing technology, image conversion generally includes operations such as image scaling. When the image scaling is performed in different ratios, because aspect ratios of a source image and a target image are not consistent, image distortion is likely to be caused. A typical application scenario is image adaptation between images that have aspect ratios of 4:3 and 16:9. For example, a traditional Cathode Ray Tube (CRT) television generally adopts a 4:3 image display mode, and the latest Liquid Crystal Display (LCD) television adopts a 16:9 image display mode. Therefore, a problem of non-uniform ratio resolution conversion of the images that have the aspect ratios of 4:3 and 16:9 exists.
In the image conversion, generally, human eyes are sensitive to an important content area (for example, an area with words) in the image, so when the image scaling is performed in different ratios, the word area in the image shall be retained as much as possible and the distortion shall be as small as possible. The image scaling from the aspect ratio of 4:3 to the aspect ratio of 16:9 in a video conference scenario is taken as an example. In the prior art, a simplest linear scaling algorithm is generally adopted. In this case, an important content area, such as words in the image, is greatly distorted. Moreover, a cropping algorithm may also be adopted to perform cropping on edges of an image, so that an aspect ratio of a cropped area is consistent with that of a target image. In this case, image distortion is not caused, but all or a part of a word area of the image is likely to be lost.
During the research and implementation of the method, the inventors of the present invention find that: in the image conversion method in the prior art, an important content area, such as a word area in the image is likely to be distorted or to be lost.